Isobaric and hyperbaric bupivacaine 0.5% solution for spinal anesthesia

The effects of spinal anesthesia with 0.5% isobaric and hyperbaric (8% glucose) bupivacaine were investigated in 45 patients who had lower limb or lower abdominal surgery. The patients were divided into 3 groups. Group 1 patients received 3 ml of 0.5% isobaric bupivacaine. The patients in group 2 and 3 received 3 or 2 ml of 0.5% hyperbaric bupivacaine (8% glucose). Blood pressure dropped in all groups. The decrease in blood pressure was so severe in group 2 that vasopressors were required in 70% of cases. The average segmental level of analgesia was T9 in group 1, C8 in group 2 and T4 in group 3. Complete motor blockade was obtained in all the patients. Time to complete motor blockade of the lower limbs was 12.6 min in group 1, 5.5 min in group 2 and 8.4 min in group 3. Duration of analgesia and motor blockade were 387.4 min and 303.7 min in group 1, 373.5 min and 300.0 min in group 2 and 318.9 min and 228.9 min in group 3. These results suggest that adequate surgical anaesthesia could be obtained with 3 ml of 0.5% isobaric bupivacaine and 2 ml of 0.5% hyperbaric bupivacaine.     

Effectiveness of isobaric 0.5% bupivacaine and 5% lidocaine in continuous subarachnoid anesthesia with microcatheters

OBJECTIVES: To study the clinical effect of two isobaric local anesthetics infused through microcatheters for continuous subarachnoid anesthesia. MATERIAL AND METHODS: Patients undergoing surgery under continuous subarachnoid anesthesia were enrolled prospectively over 12 months. Twenty-seven-gage catheters were inserted through 22 G Sprotte (Intralong) needles. The two isobaric anesthetics (0.5% bupivacaine and 5% lidocaine) were studied in two successive six-month periods. One milliliter of local anesthetic was administered, followed by incremental doses of 0.5 ml until the required anesthetic level was reached. Hemodynamic variables were recorded, as were levels of anesthetic and motor blockade and complications developing during the surgical and postoperative periods. RESULTS: Thirty-one patients were anesthetized with isobaric 0.5% bupivacaine and 40 with isobaric 5% lidocaine. A high blockade was observed in three patients in the bupivacaine group and in 15 in the bupivacaine group (p < 0.05). The highest anesthetic level reached was T4. Hypotension occurred in one patient in the bupivacaine group and in 10 in the lidocaine group (p < 0.05). Blockade was difficult to increase to the appropriate level in 11 lidocaine patients and in one bupivacaine patient, whereas blockade of distal roots was difficult in 13 bupivacaine patients and in 7 lidocaine patients (p < 0.005). The total doses infused were 11.0 +/- 3.0 mg of 0.5% bupivacaine and 95.6 +/- 24.6 mg of 5% lidocaine. CONCLUSIONS: Isobaric 0.5% bupivacaine provides a more predictable anesthetic blockade with greater hemodynamic stability and a lower rate of difficulty in raising the level of blockade than does 5% lidocaine when administered through microcatheters for continuous subarachnoid anesthesia.     

Influence of injection speed of the spread of 4.0 ml of 0.5% isobaric bupivacaine in spinal anesthesia

Influence of injection speed on the spread of isobaric 0.5% bupivacaine 4.0 ml was studied in 100 patients to analyze the correlation between analgesia levels and patient's characteristics. All patients (ASA PS I.II) were scheduled for orthopedic or urological procedures, and received no premedication. They were randomly divided into two groups by injection speed; group 1 of 0.2 ml.sec-1 and group 2 of 0.03 ml.sec-1. Spinal tap was performed in lateral decubitus position at the L 3-4 intenspace with median approach, using a 25 G Quincke needle. Immediately after the injection, the patient was placed in supine position. The maximum sensory block was tested by pinprick method, and no significant difference in the height of sensory block was observed between the two groups. No significant correlation with patient's characteristics was observed except body weight in group 1. This study suggests that the speed of injection does not influence the spread of isobaric 0.5% bupivacaine 4.0 ml.     

Spinal anesthesia with 0.5% isobaric bupivacaine for a patient with alcoholic cardiomyopathy

A 69-year-old male patient with alcoholic cardiomyopathy was scheduled for inguinal herniorrhaphy. Spinal anesthesia was performed with 1.5 ml of 0.5% isobaric bupivacaine at the L 2-3 interspace. The analgesic levels were at the eighth thoracic 15 minutes after injection and the fifth thoracic dermatome at the end of the operation, respectively. The hemodynamic status was stable during operation and his postoperative course was uneventful. This case suggests that spinal anesthesia with 0.5% isobaric bupivacaine is useful for inguinal herniorrhaphy in the patient with alcoholic cardiomyopathy.     

Investigation of 121 cases of spinal anesthesia with plain 0.5% bupivacaine

Bupivacaine has been used for spinal anesthesia since 1982 in our department. We performed a retrograde investigation of 121 cases who had lower limb surgery and anesthetized with plain 0.5% bupivacaine solution during the year of 1987. Doses of bupivacaine, maximum spread of analgesia and spinal tap level were analyzed. We chose the bupivacaine doses from 2.5 ml to 4.0 ml depending on the condition of the patient and the specificity of the surgery. The patients were divided into 3 groups by the dose of bupivacaine: i.e. 3.0, 3.5, 4.0 ml of plain 0.5% bupivacaine. Seventy percent of all patients had a spinal tap on L3/4 interspace. The average upper level of analgesia was T7 in each group and no patient had analgesia above T2 level. There was no correlation between the site of injection and volume of local anesthetics. However patient's physical status and surgical procedure are more important to obtain the good analgesic level. There was no significant respiratory depression nor hypotension during and after the surgery. It is concluded that 3-4 ml of 0.5% bupivacaine provided satisfactory spinal anesthesia for the lower limb surgery.     

Spinal anesthesia with isobaric 0.5% bupivacaine for lower limb surgery: effects of different volumes

BACKGROUND: The effects of different volumes (2.4, 2.6, 2.8 and 3.0 ml) of isobaric 0.5% bupivacaine used for spinal anesthesia were compared in 206 patients scheduled for lower limb surgery. METHODS: The spinal anesthesia was performed with the patients in the lateral position and the isobaric 0.5% bupivacaine was injected intrathecally at the L3-4 interspace. RESULTS: The time to maximum cephalad spread of anesthesia (loss of cold sensation) varied between 25 and 40 min. A significant difference was found in cephalad spread between 2.4 ml group and 3.0 ml group (T11 vs T7), and between 2.6 ml group and 3.0 ml group (T11 vs T7). Severe hypotension did not occur during the study. CONCLUSIONS: Spinal anesthesia with 2.8 ml of isobaric 0.5% bupivacaine proved satisfactory for lower limb surgery.     

The temperature of bupivacaine 0.5% affects the sensory level of spinal anesthesia

Three milliliters of plain bupivacaine 0.5% was injected intrathecally in two groups of 20 patients. Group 1 received a solution that had been equilibrated to 37 degrees C, group 2 received a solution that had been equilibrated to 4 degrees C. Patients were kept sitting for 3 minutes after injection. All observations were observer-blind. The differences between segmental levels of sensory loss between groups 1 and 2 (T4 and T9, respectively) and of temperature loss (T3 and T8, respectively) 10 and 20 minutes after injection of bupivacaine were statistically significant. It is concluded that the time needed for thermal equilibration in the cerebrospinal fluid and hence temperature of the injected solution plays an important role in the sensory spread of plain bupivacaine 0.5%.     

The influence of baricity on differential blockade with 0.5% bupivacaine spinal anesthesia

We evaluated the influence of baricity on differential blockade during spinal anesthesia using isobaric or hyperbaric 0.5% bupivacaine. Forty ASA-PS I-II patients scheduled for elective surgery (orthopedic, lower abdominal and urologic) were divided into two groups; group H, using hyperbaric 0.5% bupivacaine, and group I, using isobaric 0.5% bupivacaine. Spinal anesthesia was performed in lateral decubitus position, using a 25-gauge Quincke needle at L2-3 interspace, and 0.5% bupivacaine 2.0 ml was injected for 10 seconds. Patients were turned to supine position soon after the spinal anesthesia and the block levels were examined every 5 min for 30 min. Sympathetic blockade was detected by observer's hand, the loss of cold sensation by alcohol sponge and the loss of pain sensation by pinprick. Complete motor blockade was detected by modified Bromage scale. Significant higher sensory blockade and large number of complete motor block were observed in group H. Differential blockade between sympathetic and sensory was significant and lasted 30 min in group I, but lasted only 15 min in group H.     

坐位细针腰麻在急诊剖宫产术中的临床应用

目的探讨坐位细针腰麻在急诊剖宫产术中的临床应用效果。方法选择急诊剖宫产术产妇400例,美国麻醉医师协会（ASA）分级Ⅰ～Ⅱ级,按照随机数字表法分为4组（每组100例）：A组,坐位笔尖样细针腰麻组;B组,侧卧位笔尖样细针腰麻组;C组,坐位普通斜面针腰麻组;D组,侧卧位普通斜面针腰麻组。穿刺成功后注入0．5％布比卡因1．8ml～2．2ml（9mg—11mg）。术毕待麻醉平面消散至T10以下后,送回病房去枕平卧6h,第1、2、3天及时随访。观察记录4组产妇的血压、脉搏血氧饱和度和心率的变化,记录腰麻穿刺次数、穿刺成功率、麻醉操作时间、穿刺开始到切皮时间、切皮到胎儿娩出时间以及术中、术后副作用。结果与B组和D组比较,A组和C组（即两组坐位与两组侧卧位比较）穿刺次数减少[B组（3．2±0．9）和D组（4．1±0．4）,A组（1．1±0．5）和C组（1．2±0．6）]、穿刺成功率提高[B组（90％）和D组（92％）,A组（100％）和C组（98％）]、穿刺时间缩短[B组（5．2±0．6）min和D组（4．1±0．9）min,A组（1．2±0．8）min和C组（2．1±0．7）min]、麻醉操作时间缩短[B组（7．1±0．5）min和D组（6．2＋0．8）min,A组（3．4±0．7）min和C组（4．3±0．6）min]、从穿刺开始到切皮时间缩短[B组（15．2±6．3）min和D组（17．1±4．4）min,A组（10．4±0．5）min和C组（11．3±0．7）min]（P〈0．05）。与C组和D组比较,A组和B组（即两组细针与两组普通针比较）术中低血压发生率降低[C组（18％）和D组（20％）,A组（8％）和B组（10％）]、恶心呕吐发生率减少[C组（10％）和D组（12％）,A组（4％）和B组（5％）]、无术后头痛和腰痛发生[C组（3％）和D组（4％）,A组（0）和B组（0）]（P〈0．05）。结论坐位细针腰麻,操作简便,所需时间短,穿刺次数少,成功率高,术中、?     

Extent of hyperbaric spinal anesthesia influences the duration of spinal block

BACKGROUND: The influence of spread of spinal anesthesia on the duration of spinal blockade has been suggested but never investigated specifically. Because elimination of local anesthetic from subarachnoid space is probably dependent of the surface available for its diffusion and vascular absorption, the current study was designed to evaluate the hypothesis that with a same dose of hyperbaric bupivacaine, a higher anesthetic level would result in a shorter duration of spinal blockade than a lower level. METHODS: Three milliliters (15 mg) of hyperbaric bupivacaine, 0.5%, was injected intrathecally in 40 patients classified as American Society of Anesthesiologists physical status I or H scheduled for lower limb surgery during spinal anesthesia. To obtain significantly different anesthetic levels, the patients were positioned randomly either horizontally or with the torso elevated 30. Regression of sensory level and motor blockade, the appearance of pain at the operative site, and hemodynamic changes were evaluated. RESULTS: The maximum cephalad spread of sensory blockade (expressed as the median with ranges in parentheses) was significantly higher in the horizontal group than in the group with 30-degree elevation of the torso, i.e., T3.5 (T1-T9) versus T10 (T6-L1), with respectively significantly faster regression times (mean ? SD) by two segments (216 ? 46 mm vs. 253 ? 64 mm) and to segment L4 (269 ? 53 mm i s. 337 ? 58 mm), as well as shorter time to complete motor blockade recovery (173 ? 34 mm i s. 233 ? 58 mm) and faster appearance of pain at the operative site (221 ? 68 mm vs. 271 ? 56 mm). CONCLUSION: The results indicate that with the same dose of hyperbaric bupivacaine, the duration of spinal blockade is longer in patients with restricted spread.     

A comparison of levobupivacaine 0.5% and racemic bupivacaine 0.5% for extradural anesthesia for caesarean section

BACKGROUND AND OBJECTIVES: Bupivacaine is available as a racemic mixture of its enantiomers, dextrobupivacaine and levobupivacaine. Both in vitro and in vivo studies show that dextrobupivacaine has a greater inherent central nervous system (CNS) and cardiovascular toxicity than levobupivacaine. Clinical studies show levobupivacaine to have similar local anesthetic potency to the racemate. The aim of this study was to investigate the clinical efficacy and safety of levobupivacaine compared with racemic bupivacaine for extradural anesthesia. METHODS: We studied 62 patients undergoing elective caesarean delivery who received 25 mL of either levobupivacaine 0.5% or bupivacaine 0.5%, extradurally, in a randomized, double-blind study. RESULTS: The 2 groups were similar in terms of time to block suitable for surgery, segmental spread, and duration of sensory block. However, lower-limb motor block was significantly longer in the levobupivacaine group but of significantly less intensity. CONCLUSIONS: Levobupivacaine produces an extradural block that is similar to bupivacaine, and is a suitable local anesthetic agent for caesarean delivery.     

Micturition disorders following spinal anesthesia of different durations of action (lidocaine 2% versus bupivacaine 0.5%)]

Disturbances of micturition following spinal anaesthesia are considered to be rare and harmless side effects of this technique. For this reason, we set up a prospective study to investigate their incidence, characteristics and intensity. Our special interest was directed at the influence of the duration of action of local anaesthetics. METHODS. In a randomized, double-blind study, two groups, each consisting of 73 trauma surgical and orthopaedic patients, received isobaric spinal anaesthesia with either lidocaine 2% or bupivacaine 0.5%. From the 1st to the 3rd postoperative day, the patients were interviewed daily and asked specifically about disturbances of micturition. RESULTS. The two groups were comparable in terms of clinical data, spinal anaesthesia and surgery. Disturbances of micturition occurred only during the first 24 h and were observed in a total of 42%. They were about twice as frequent after bupivacaine (56%) as following lidocaine (27%). After bupivacaine there was a higher rate of difficult micturition or complete inability to micturate in the presence of an urge to urinate, carbachol medication and catheterization of the urinary bladder. Sex and age had no influence on the incidence. A history of disturbances of micturition increased their frequency. DISCUSSION AND CONCLUSIONS. Disturbances of micturition are the most common side effect of spinal anaesthesia during the first 24 h after surgery. Their higher frequency following the longer acting bupivacaine may be evidence of longer lasting blockade of the efferent sacral parasympathetic fibers innervating the detrusor vesicae muscle, leading to inhibition of bladder voiding. The consequences of these disturbances, if not correctly managed, may be distension of the urinary bladder with ensuing infection and loss of tone of the detrusor muscle. Various measures are recommended: choice of the longer acting local anaesthetic only if necessary, careful control of bladder filling, restrictive infusion of fluids, early mobilization, carbachol, catheterization in good time, prophylactic placement of an indwelling catheter in patients with previous disturbances.     

Comparison of 0.5% ropivacaine and 0.5% bupivacaine for epidural anesthesia in patients undergoing lower-extremity surgery

Ropivacaine is an amide local anesthetic structurally related to, but appearing less cardiotoxic, than bupivacaine. The authors' investigation was designed in a randomized, double-blind fashion to compare the clinical effectiveness of ropivacaine and bupivacaine in patients undergoing lower-extremity surgery. Forty-five patients were randomized to receive 20 ml of 0.5% ropivacaine or bupivacaine. Intermittent sensory (pinprick) and motor (Bromage score) measurements were made while the block was in effect, and changes in heart rate, blood pressure and amounts of additional analgesics, sedatives and other medications were also recorded. Presence of tourniquet pain and the quality of anesthesia were also assessed. One patient was excluded from analysis; thus, 22 patients each received ropivacaine or bupivacaine. No differences were found in patient or perioperative characteristics between the groups. The quality and extent of sensory and motor blockade between groups were comparable, although bupivacaine was slightly longer acting. Cardiovascular changes, incidence of tourniquet pain, and the amounts of supplemental medications necessary were also similar between groups. The authors found 0.5% ropivacaine and bupivacaine to be clinically similar in both sensory- and motor-blocking characteristics, with the exception that bupivacaine produced a blockade of slightly longer duration. Because ropivacaine is reported to be less cardiotoxic than bupivacaine in animal studies, the similarity of clinical epidural anesthesia may make ropivacaine the preferred agent.